Should you give up gluten?

Thanks to celebrities like Miley Cyrus and Gweneth Paltrow, ditching gluten to shed some pounds can seem like a genius idea. Except that it’s not—and the 1.6 million people avoiding gluten without an intolerance or an allergy aren’t doing themselves any favors, finds new research in the American Journal of Gastroenterology.

Researchers from the Mayo Clinic found that about 80 percent of people who don’t eat gluten—a protein found in wheat and other grains—are following the diet despite never having been diagnosed with celiac disease, the genetic disorder that causes an autoimmune reaction to gluten. On the other hand, of the 1.8 million Americans who have celiac, 1.4 million of them are unaware that they have it.

“One percent of the population, and one in 100 Caucasians, has celiac,” said Dr. Joseph Murray, a Mayo Clinic gastroenterologist who co-authored the study. “Only 17 percent of them know. Some of them have gastrointestinal complaints, but a lot do not.”

Experts know much more now about celiac than they did even a decade ago—so why are so many people going undiagnosed?

“Undiagnosed celiac does not necessarily mean it’s without symptoms—just that they haven’t been enough or specific enough to have triggered testing,” Murray said.

And the rise in the popularity of gluten-free diets has only made things more confusing.

“Once you go on a gluten-free diet, all of the tools to understand where you are on the spectrum are gone,” said Dr. Alessio Fasano, founder and director of the University of Maryland Center for Celiac Research. In order for a blood test to detect the biomarkers for celiac, you have to actually eat gluten.

Here’s what to do if you suspect you may have celiac or gluten sensitivity:

Know the symptoms. Celiac and gluten sensitivity are “a clinical chameleon,” Fasano said. Anyone who exhibits GI symptoms like stomachache, diarrhea, bloating, gas, and unexplained weight loss should be tested, he says—but you should also take note if you have joint pain without arthritis, anemia that’s not corrected by iron supplements, have had miscarriages without a clear reason, or have type 1 diabetes.

Talk to your doc before changing your diet. “If the blood test comes back positive, it’s not absolute that you have celiac, but it makes it more likely,” Murray said. “Then you’ll need an intestinal biopsy to be sure.”

If testing indicates you have celiac, you’ll need to follow a gluten-free diet for life. If you do not have celiac, going on a supervised gluten-free or low-gluten diet may help determine if you're gluten-sensitive.

Be honest about whether it’s working. “Generally speaking, a patient who has the typical symptoms of gluten sensitivity will go on a gluten-free diet and feel dramatically better,” Murray said. “But dietary changes can have placebo effects."

Sometimes people who were overeating before might feel better on their gluten-free diet simply because they’re now eating less. If after four months your symptoms return, he says, you probably don’t need to stay on it.

Make sure you’re getting the right nutrition. Another reason it's important to get a doctor's supervision: Cutting out gluten and wheat products means missing out on all the vitamins and minerals found in this wide range of foods. A dietitian can recommend alternative foods and supplements to make sure you're hitting your recommended amounts.